This invention relates in general to turbine blades and deals more particularly with an improved convectively cooled turbine blade particularly adapted for use in the second stage of an industrial gas turbine engine.
In gas turbine engines and the like a turbine operated by burning gases drives a blower or compressor which furnishes air to a burner. Such turbine engines operate at relatively high temperatures. The capacity of such an engine is limited to a large extent by the ability of the material from which the turbine blades are made to withstand thermal stresses which develop at such relatively high operating temperatures. The problem may be particularly severe in an industrial engine because of the relatively large size and mass of engine parts. To enable higher operating temperatures and increased engine efficiency without risk of blade failure, hollow convectively cooled turbine blades are frequently utilized. Such blades generally have intricate interior passageways which provide torturous flow paths to assure efficient cooling whereby all portions of the blades may be maintained at relatively uniform temperature. However, such blades are difficult and expensive to manufacture. The present invention is concerned with this problem, and it is the general aim of this invention to provide an improved convectively cooled turbine blade which satisfies required design criteria and which may be manufactured at relatively low cost and up-rated for increased cooling without expensive reoperation or redesign.